Week 1 Neuroanatomy 1 of 4 Flashcards
Spinal block?
small amount of LA is injected directly into the CSF. -it produces an intense, rapid, and predictable neural blockade
Epidural Block?
It requires a tenfold increase in dose to fill the epidural space and penetrate the nerve roots. -it has a slower onset.
What is a caudal block?
injecting into the sacral hiatus
A caudal block is a pain relief technique that’s characterized by the injection of LA and anti-inflammatory medications into the lower sacral bone of the spine. It’s most commonly used on infants and children ** not in mo’s powerpoints but the concept was an objective**
Identify the Intervertebral foramen in the image:
red outline b/w verterbrae
Locate the intervertebral disc in the image:
spongey like substance b/w two discs
Typical vertebra consist of 5 things:
- Body 2. vertebral arch 3. Seven Processes 4. Vertebral Foramen 5. Vertebral notches –> Processes
The vertebral arch is formed by
pedicles and laminae
The function of the seven processes is for:
-muscle attachment -
The function of the seven processes is for:
-muscle attachment - formation of vertebral foramen
The vertebral canal that houses the spinal cord is:
the vertebral foramen
Name (and number of) the different types of vertebral processes
7 total: - Spinous (1) - Transverse (2) - Articular processes (4)
Role of Articular processes
to connect adjacent vertebrae
Spinal cord ends at
L2-L3
Conus medullaris at
L1-L2
Dural Sac ends at
S2
Number of vertebra in cervical (c) spine?
7 (c1-c7)
Number of vertebra in Thoracic (T) spine?
12 (T1-T12)
Number of vertebra in Lumbar (L) spine?
5 (L1-L5)
The sacrum is a fusion of
5 sacral (s) vertebrae. (S1-S5)
The role of the Internal and External terminal filum is to
anchor the spinal cord *fibers!! no feelings*
Ligamentous elements provide:
-structural support -with supporting muscles; help maintain the unique shape.
Ligamentous elements provide:
-structural support -with supporting muscles; help maintain the unique shape.
The name for the “horse tail”
Cauda Equina
Internal Terminal Filum role:
Anchors Pial Aspect of spinal cord
External Terminal Filum role:
Anchors Dural aspect of spinal cord
Name of area where spinal cord terminates
Conus medullaris
important anatomical landmark for head down position of fetus:
anterior Sacral promontory
Distinguishing feature of Coccyx
Fused together *so are the sacral vertebrae but he didn’t mention it specifically
Identify: -Dura -Arachnoid - Epidural Space -Pia -Subarachnoid space
B -Dura C -Arachnoid F - Epidural Space H -Pia I -Subarachnoid space
Identify epidural vs spinal in image:
A - Epidural B- Spinal
Lumbar region is generally safer for injection due to what reason?
No structures that can be harmed by needle -all cauda equina
Lumbar region is generally safer for injection due to what reason?
No structures that can be harmed by needle -all cauda equina
What position is ideal for lumbar puncture?
maximum flexion “think like shrimp”
Name the anatomical landmarks for locating L4
Superior iliac crest
Name the anatomical landmarks for locating L4
Superior iliac crest
What is a lumbar puncture?
when CSF is obtained from the lumbar subarachnoid space
What subarachnoid space is pierced in a lumbar puncture?
L4 &L5
Name structures (in order) pierced in spinal :
Skin Subcutaneous Tissue Supraspinous Ligament Interspinous Ligament Ligamentum Flavum Epidural Space Dura Mater Subdural Space Arachnoid Mater Subarachnoid space “Some say sister Ida loves doing acid”
Name structures (in order) pierced in epidural:
Skin Subcutaneous Tissue Supraspinous Ligament Interspinous Ligament Ligamentum Flavum Epidural Space
in a lateral approach, what structures will you NOT pass through?
Supraspinous and interspinous ligaments
Resting state of the action potential is what voltage?
-70mV - -90mV
at rest, the nerve membrane is more permeable to
K+ (than to Na+)
Leaky K+ channels are responsible for
resting membrane potential
the Na+/K+ pump maintains
resting membrane potential
Na/K pump ratio
3 Na OUT and 2 K IN
Nerve Impulse (action potential) is a property of
Excitable cells (nerve, muscles)
Excitable cells that consist of a rapid depolarization (or upstroke) and is followed by
Repolarization of membrane potential
Upstroke of the AP (depolarization) is:
- Inward Na+ movement 2. Lidocaine block these voltage sensitive Na+ ch and abolish AP.
Lidocaine blocks the
voltage sensitive Na+ ch and abolish AP.
Downstroke of the AP (repolarization) is:
- Outward K+ movement 2. Inward current (flow of Na+ into the cell) depolarizes the membrane potential, while outward flow of K+ hyperpolarize the Membrane potential.
Na and K flow by
simple diffusion
Action potential is constant
shape and size
action potential follows which law?
all or none (no percentage)
Threshold is the membrane potential at which:
the AP is inevitable
Propagation or spread of AP
60 m/ sec Myelinated vs Non-Myelinated fibers
Refractory Period
Due to closure of inactivation gates of Na+
absolute refractory period is a period during which
another AP cannot be elicited, no matter how large the stimulus. -Due to closure of inactivation gates of Na+
Relative refractory period is a period during which
an AP can be elicited ONLY if a larger than usual stimulus is provided.
Purpose of a refractory period
-protect the cell from over-excitation. -it allows a recovery period b/w the AP’s.
What protects the cell from over-excitation.
Refractory period
